Have you encountered a valve that wont open with a timer? Is power going to the solenoid but is not turning on the valve? Are you required to manually open the valve? In situations like these, it is likely that you are experiencing a faulty solenoid.
Based on some of the symptoms listed above, you might be having an electrical problem with a valve somewhere in the system. If you have a multi-meter or an irrigation test kit, you can easily do some basic checks around the solenoid and valve.
Identifying the Components
First, let’s identify the electrical component. The electrical component is called the solenoid. Inside the solenoid there is a small plunger that is electrically activated. Below are some images that give you an idea of where the solenoid is located as well as how it operates with the valve:
Solenoid Location on Valve
Solenoid and Valve Working Together
The solenoid has two wire leads coming out the top and is located on top of the valve (see Image below). For most valves, the solenoid is powered by an irrigation controller that supplies a 24 volt alternating current. In the case of a battery timer, the solenoid is different and is activated by direct current supplied by the battery in the controller.
Valve Test Procedure:
- Turn off the water supply to the irrigation system using an isolation valve
- Disconnect the solenoid wires from the controller
- Using and multimeter test the number of ohms through the solenoid
- 20-60 ohms – Good
- 10 ohms or less – short in solenoid (replace solenoid)
- Over 60 ohms – usually no connection
- Try cutting off 3 or 4 inches of solenoid wire and retesting
- If still over 60 ohms, replace solenoid
- If solenoid tests Good, then the solenoid is OK.
Solenoid Multi-Meter Reading
If the solenoid is OK but the valve is not working, consult the blog posts on testing irrigation wiring and troubleshooting irrigation valves.